AdaM : adaptive-maximum imputation for neighborhood-based collaborative filtering

In the context of collaborative filtering, the well known data sparsity issue makes two like-minded users have little similarity, and consequently renders the k nearest neighbour rule inapplicable. In this paper, we address the data sparsity problem in the neighbourhood-based CF methods by proposing an Adaptive-Maximum imputation method (AdaM). The basic idea is to identify an imputation area that can maximize the imputation benefit for recommendation purposes, while minimizing the imputation error brought in. To achieve the maximum imputation benefit, the imputation area is determined from both the user and the item perspectives; to minimize the imputation error, there is at least one real rating preserved for each item in the identified imputation area. A theoretical analysis is provided to prove that the proposed imputation method outperforms the conventional neighbourhood-based CF methods through more accurate neighbour identification. Experiment results on benchmark datasets show that the proposed method significantly outperforms the other related state-of-the-art imputation-based methods in terms of accuracy.

Differential privacy for neighborhood-based collaborative filtering

As a popular technique in recommender systems, Collaborative Filtering (CF) has received extensive attention in recent years. However, its privacy-related issues, especially for neighborhood-based CF methods, can not be overlooked. The aim of this study is to address the privacy issues in the context of neighborhood-based CF methods by proposing a Private Neighbor Collaborative Filtering (PNCF) algorithm. The algorithm includes two privacy-preserving operations: Private Neighbor Selection and Recommendation-Aware Sensitivity. Private Neighbor Selection is constructed on the basis of the notion of differential privacy to privately choose neighbors. Recommendation-Aware Sensitivity is introduced to enhance the performance of recommendations. Theoretical and experimental analysis are provided to show the proposed algorithm can preserve differential privacy while retaining the accuracy of recommendations.

Transiting with the environment: an exploration of traveller’s reorientations as creative and collaborative practice

Travellers undertake a process of reorientation and realignment that is particular to each destination. This process intensifies when travelling long distances across borders, cultures and climates, as travellers utilise performative, embodied and creative methods that respond to each new environment. Certain destinations, such as those with unique and extreme natural environments, induce a socio-cultural imaginary that primes travellers for what kind of experience they might have. Large, immersive landscapes and climates congeal with expectations of what each destination requires in order to navigate through it. Common bearings of distance and scale are skewed, as travellers are positioned within areas of vastness. In these moments immersive experiences contrast with daily processes, such as the act of packing a bag, as this heightened sensory awareness exacerbates the subtle material and spatial negotiations. Utilising interviews and photographic documentation of travellers to Iceland and Nepal, this paper develops the proposal that certain destinations intensify our attunement to these moments of reorientation, facilitating situated and creative methods.

As recent developments in the fields of mobilities and tourism draws attention to material interactions during travel, and current ‘new materialism’ movements in theory and practice reveal alternative affective methods of engagement, an exploration of interactions with/in immersive sites is needed in order to evaluate the potential that these kinds of transitions offer everyday experiences of movement. Nigel Thrift’s proposition of Non-Representational Theory provides clarity on the ways in which spatial awareness influences such transitions and environmental experiences. Using his acknowledgement of a more ontologically driven responsiveness to space, this permits a shift away from the presupposed containment of spaces as isolated destinations, toward a relational spatiality that encompasses all actors – including environments – as vital elements in the generative processes of situating our movements.

Creative strategies that afford sensory, aesthetic and embodied performances provide ways to examine these experiences, providing a multitude of possibilities as individual experiences shift towards collective and collaborative performances, as we are immersed within a range of human and non-human actors. This paper explores the transition away from ‘consuming’ environments, and advocates for the need to turn towards a situated collaboration with environments, propelling an awareness of sustainable and creative travel practices. An understanding of affirmative differences is required within travel cultures, rather than expressing transitions as confined within the ‘home’ versus ‘away’ dichotomy that lingers from elite western travel narratives. In order to undertake the many movements required, this paper draws on the theoretical approaches of sustainable nomadism as described by Rosi Braidotti to highlight the linkages of environmental and bodily experiences.

Through multidisciplinary literature, interviews and personal reflections, this paper proposes that certain destinations amplify processes of alignment with the environment, developing affective, embodied and situated experiences that overcome the human/non-human divide.

Souvenirs of the senses: collaborative and cross-artform makings

Souvenir hunters are often limited in their selection of souvenirs to objects that evoke an iconic and/or generic relationship to place. For example, a small-scale replica of the Eiffel Tower might substitute for a whole range of other more personal responses to the sensory experience of being in Paris. This paper reports on a collaborative and cross-artform five-day workshop, “Souvenirs of the Senses”, conducted in Qatar in early 2013 as part of Tasmeem Doha: Hybrid Making, a biennial international art and design conference. Two of the three workshop leaders, Patrick West and Jondi Keane, were Australian-based visitors whereas workshop leader Valerie Jeremijenko is permanently based in Qatar. There were five workshop participants from a diverse range of international and Qatari backgrounds. One of the conference themes, “Made in Qatar”, heightened our attention to what it means to be spending time in, and making things in, one place as opposed to any other place. What did it mean to be making something in a country where so many things have to be imported? Building on this line of thought, the second conference theme, “Hybrid Making”, suggested possibilities for undoing traditional modes of souvenir making as part of the creation of more complex objects that might be sutured to the singular experiences of place that happen when a.) established regimes of tourism are disrupted, and b.) experiences of place are curated via a focused awareness of the operations of the senses as sustained within our collaborative, cross-artform workshop environment. What attracts our attention is how objects ripe for “souveniring”, when they are considered as perceptual systems, suggest new ways of experimenting with the fabrication of objects and of artistic and individual relationships to place, and further, how hybrid souvenirs affect the way in which a place is re-membered (put together) and re-made in memory.

Dancing in suits: a performer's perspective on the collaborative exchange between self, body, motion capture, animation and audience

The motion capture process places unique demands on performers. The impact of this process on the simultaneously artistic/somatic nature of dance practice is profound. This paper explores, from a performer’s perspective, how the process of performing in an optical motion capture system can impact and limit, but also expand and reconfigure a dancer’s somatic practice. This paper argues that working within motion capture processes affects not only the immediate contexts of capture and interactive performance, but also sets up a dialogue between dance practices within and beyond the motion capture studio.

Postcolonial theory and cross-culturalism : collaborative ‘signposts’ of discursive practices

This paper is a forerunner of a detailed piece of work. It explores the notions of postcolonial theory and cross-culturalism, and whether they can be regarded as collaborative ‘signposts’ of discursive practices. The aim of this paper is to move beyond the contemporary constructs of race, culture and identification and into the arena of hybridity and multiplicity and the constituting and reconstituting of self. In this discussion, I will first outline the notions of postcolonial theory and cross-culturalism, and then explore focal points of collaborative discursive practices. In doing so, I will discuss perceptions of language and discourse and their relationships to postcolonial theory and cross-culturalism. In the context of this topic, I shall use Australia as an example of a diverse community and English as the language being discussed under the term ‘discursive practices’.

The prevalence and risk factors of epiretinal membranes: the Melbourne collaborative cohort study

Purpose
To determine the prevalence of epiretinal membranes (ERMs) in Melbourne, Australia and its risk factors in this population.

Methods
The Melbourne Collaborative Cohort Study is a prospective study investigating the role of diet and life style in the causation of common chronic diseases. Eighty-six percent of participants were of Northern European origin born in Australia or United Kingdom and 14% were migrants from Greece or Italy (Southern European origin). Nonmydriatic digital retinal photography was implemented at Melbourne Collaborative Cohort Study follow-up. The ERMs were recorded as cellophane macular reflex without retinal folds or preretinal macular fibrosis (PMF) with retinal folds.

Results
A total of 22,406 participants had retinal photography, 95% (n = 21,241) were eligible for ERM grading. The ERM prevalence were 8.9% (1,882); cellophane macular reflex, 4.9% (1,047); and preretinal macular fibrosis, 3.9% (835). After adjustment for age, sex, level of education, smoking status, level of cholesterol, body mass index, waist-to-hip ratio, waist measurement, blood pressure, diabetes, and stroke, increasing age and Southern European ethnicity was significantly associated with ERMs. Overall, in Southern Europeans, ERMs odd ratio was 1.97 (95% confidence intervals, 1.67–2.31), P < 0.001; preretinal macular fibrosis was 1.82 (95% confidence intervals, 1.43–2.31), P < 0.001; and cellophane macular reflex was 1.93 (1.57–2.38), P < 0.001.

Conclusion
In an older Australian population, the prevalence of ERMs was 8.9% and was almost two times higher in participants of Southern European origin than Northern European origin.

Protocol for a collaborative meta-analysis of 5-HTTLPR, stress, and depression

Background: Debate is ongoing about what role, if any, variation in the serotonin transporter linked polymorphic region (5-HTTLPR) plays in depression. Some studies report an interaction between 5-HTTLPR variation and stressful life events affecting the risk for depression, others report a main effect of 5-HTTLPR variation on depression, while others find no evidence for either a main or interaction effect. Meta-analyses of multiple studies have also reached differing conclusions.

Methods/Design: To improve understanding of the combined roles of 5-HTTLPR variation and stress in the development of depression, we are conducting a meta-analysis of multiple independent datasets. This coordinated approach utilizes new analyses performed with centrally-developed, standardized scripts. This publication documents the protocol for this collaborative, consortium-based meta-analysis of 5-HTTLPR variation, stress, and depression.

Study eligibility criteria: Our goal is to invite all datasets, published or unpublished, with 5-HTTLPR genotype and assessments of stress and depression for at least 300 subjects. This inclusive approach is to minimize potential impact from publication bias.

Data sources: This project currently includes investigators from 35 independent groups, providing data on at least N = 33,761 participants.  The analytic plan was determined prior to starting data analysis. Analyses of individual study datasets will be performed by the investigators who collected the data using centrally-developed standardized analysis scripts to ensure a consistent analytical approach across sites. The consortium as a group will review and interpret the meta-analysis results.

Discussion: Variation in 5-HTTLPR is hypothesized to moderate the response to stress on depression. To test specific hypotheses about the role of 5-HTTLPR variation on depression, we will perform coordinated meta-analyses of de novo results obtained from all available data, using variables and analyses determined a priori. Primary analyses, based on the original 2003 report by Caspi and colleagues of a GxE interaction will be supplemented by secondary analyses to help interpret and clarify issues ranging from the mechanism of effect to heterogeneity among the contributing studies. Publication of this protocol serves to protect this project from biased reporting and to improve the ability of readers to interpret the results of this specific meta-analysis upon its completion.